Process for preparing 2',3',5'-tri-0-acetyl-6-azauridine

Abstract

Process for preparing 2',3',5'-tri-0-acetyl-6-azauridine having the following formula ##SPC1## Which comprises reacting a crude anomeric mixture of methyl D-ribofuranosides having the formula ##SPC2## With anhydrous hydrogen chloride or anhydrous hydrogen bromide in the presence of acetic anhydride and acetic acid to thereby form the corresponding 2,3,5-tri-0-acetyl-D-ribofuranosyl halide having the formula ##SPC3## Wherein X is chloro or bromo, reacting the halide of formula III with 3,5-bis-trimethylsilyloxy-1,2,4-triazine having the following formula ##SPC4## In the presence of an inert solvent and a mercuric halide and recovering the 2',3',5'-tri-0-acetyl-6-azauridine.

We claim: 
     
       1. A process for producing 2',3',5'-tri-O-acetyl-6-azauridine having the formula: ##SPC9## which consists of the steps of reacting a crude anomeric mixture of methyl D-ribofuranosides having the formula ##SPC10##   with anhydrous hydrogen chloride or anhydrous hydrogen bromide in the presence of acetic anhydride and acetic acid to thereby form the corresponding 2,3,5-tri-O-acetyl-D-ribofuranosyl halide having the formula ##SPC11##   wherein X is chloro or bromo, and thereafter reacting the halide of formula III with 3,5-bis-trimethylsilyloxy-1,2,4-triazine having the formula ##SPC12##   in the presence of an inert solvent of a mercuric halide and recovering the 2',3',5'-tri-O-acetyl-6-azauridine.   
     
     
       2. The process according to claim 1, wherein the reaction of the compounds of formula III with the compound of formula IV is conducted at room temperature in the presence of anhydrous acetonitrile and of 0.1 - 0.5 mol equivalents of mercuric bromide. 
     
     
       3. The process according to claim 1 wherein the inert solvent is selected from the group consisting of acetonitrile, 1,2-dichlorethane, dichlormethane and chloroform. 
     
     
       4. The process according to claim 1 wherein said mercuric halide is selected from the group consisting of mercuric chloride, mercuric bromide and mercuric iodide. 
     
     
       5. The process according to claim 1 wherein said hydrogen chloride or hydrogen bromide is used in gaseous form.